The minimal flush volume for washout of preservation fluid in liver transplantation

Organ preservation is one of the important steps that predicts the patient outcome. However, after revascularization, the high concentration of potassium that influxes into the circulation might cause immediate postreperfusion hyperkalemia. To prevent this complication, the portal vein has been washed out with flush fluid to remove preservation fluid before reperfusion. Up to now, it has not been established what exact amount volume of albumin provides washout of the UW solution.

Eleven of 20 patients who underwent orthotopic liver transplantation (OLT) between December, 2003, and June, 2005, were enrolled in this study. OLT was performed following the standard technique. Five percent albumin (1000 mL) was flushed through the portal vein canula before reperfusion of the donor liver. Every 100 mL of flush fluid effluent was collected from an incomplete infrahepatic inferior vena cava anastomosis for electrolyte measurement. The 10 flushed fluid samples were measured for potassium concentration. Mean arterial pressure was monitored preoperatively, at 1-minute intervals after reperfusion and at 60 minutes after reperfusion.

We observed that 61.5% of potassium was removed after only 100 mL of flush fluid, and 90.8% after 500 mL. Only one patient in this study had an effluent potassium reduction that did not achieved 90% after 500- or 1000-mL flush. However, this patient did not develop either postreperfusion syndrome or hyperkalemia. One patient did experience postreperfusion hyperkalemia (6.20 mEq) with severe hypothermia and cardiac arrest. Five patients had stable hemodynamic profiles and five patients, transient, reversible hypotension without postreperfusion hyperkalemia.

We propose that the minimal flush volume for washout of preservation fluid in liver transplantation is 500 mL, to reduce the risk of postreperfusion syndrome and hyperkalemia.